You came to Houston to listen and learn about promise, or so you’d hoped. On a cool but clammy Sunday morning, you arrive at downtown’s Market Square Park with a couple dozen other cyclists. As you straddle your bike, you watch a tall, trim man with flecks of graying hair climb onto a decorative concrete bench. The man, a current Houston City Council member, addresses the crowd gathered around you. “I’m Steve Costello, and I’m...